Selected cladding mode recoupling based on cascaded LPG and TFBG for satellites vibration environment monitoring

摘要

Selected cladding mode recoupling between a long period grating (LPG) and a tilted fiber Bragg grating (TFBG) is demonstrated for satellites vibration environment monitoring. The mode recoupling characteristic between LPGs with different resonance wavelengths and TFBGs with different tilt angles are investigated. Strong coupling occurs between the two associated cladding modes of the same order over the overlapped resonance bands of the two gratings. Suppression ratio of over 20 dB between the recoupled cladding mode and the core reflection mode is achieved when the resonance wavelength of the LPG matches the Bragg wavelength of the TFBG. The present sensor has the features of cost-effective power detection and tip-reflection sensing ability, and give a remarkably simple and elegant approach to dynamic vibration monitoring.